Optical communication systems increasingly employ wavelength division multiplexing (WDM) techniques to transmit multiple information signals on the same fiber, and differentiate each user sub-channel by modulating a unique wavelength of light. WDM techniques are being used to meet the increasing demands for improved speed and bandwidth in optical transmission applications. For each ordered pair (Ni, Nj) of nodes in a wavelength division multiplexing network, one could assign a wavelength λij so that data sent from node Ni to node Nj is always sent on the λij wavelength along some path from node Ni to node Nj. Distinct wavelengths can be assigned to each such communicating pair of nodes, if there are a sufficient number of wavelengths available, or the same wavelength could be assigned to a number of such node pairs, provided that the paths used are disjoint. In general, however, the number of wavelengths needed is quadratic with the number of network nodes. The capacity of a wavelength, however, far exceeds the typical communication load between nodes. Thus, it would be advantageous if the capacity of a wavelength could be shared in some way.
I. Widjaja et al., “Light Core and Intelligent Edge for a Flexible, Thin-Layered and Cost-Effective Optical Transport Network,” IEEE Optical Communications, S30-36 (May, 3003) incorporated by reference herein, proposed a network architecture, referred to as Time-domain Wavelength Interleaved Networking (TWIN), that combines wavelength division multiplexing and time division multiplexing techniques. Generally, according to the TWIN architecture, each node Ni is assigned a distinct wavelength λi and all other nodes send signals to Ni using λ1 in a time-shared manner. Thus, the number of wavelengths required is equal to the number of nodes rather than quadratic in the number of nodes. Each node can then be assigned time-slot(s) in which the node is permitted to send data to node Ni with the time-slots chosen so that no two nodes send signals to node Ni in the same time slot. In addition, a node can transmit a signal to at most one node during a given time slot. Scheduling time-slots in this manner is often challenging. TWIN also requires nodes in the network to function essentially as routers where the wavelength of a signal determines the outbound link for the signal.
A need therefore exists for a system and method for time-domain wavelength interleaved networking that reduce the need for complex time-slot scheduling and reduce the routing complexity.